Summary of Mold Basics

Summary of Mold Basics

  • The quality of a mold has a direct impact on the quality of parts produced from the mold. High quality molds are often required for creating composite parts because the mold determines the shape, dimensional accuracy, and surface finish of the part. 

  • The basic shape of a mold can be classified as male, female, or closed and can contain positive, negative, and zero draft angles. The draft angle of a mold will determine how easily a part can be separated from a mold, with positive draft angles being desirable.

  • Multi-section molds may be required for large parts or parts with complicated geometry. 

  • Molds contain features and structures beyond just the tooling surface where the composite part makes contact with the mold. These additional features can aid in different aspects of the manufacturing process such as mold assembly, vacuum bagging, demolding, or part trimming. 

Aerospace Mold and Tooling Course

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Mold Basics

  • Introduction to Molds
  • Composite Manufacturing Processes
  • Basic Rules to Follow
  • Mold Terminology
  • Summary of Mold Basics

Mold Construction Methods

  • “Off-The-Shelf” Molds: Flat Plates & Extrusions
  • Single-Use Molds
  • Moldless Construction
  • Molds Made From Existing Parts (“Splash Molds”)
  • CNC Machined Molds ("Direct-to-Mold")
  • CNC Machined Patterns
  • 3D Printed Patterns and Molds1
  • Large Scale Additive Manufacturing (LSAM)
  • Summary of Mold Construction Methods2

Mold Materials

  • Overview of Foam Materials
  • Rigid Foam and Tooling Board
  • Casting Foam
  • Tooling Paste
  • 3D Printed Plastics
  • MDF and Engineered Wood2
  • Gel Coat
  • Fiber-Reinforced Composites
  • Aluminum & Steel
  • Other Materials
  • Summary of Mold Materials

Mold Design

  • Establishing Mold Requirements
  • Design Requirement - Cost
  • Design Requirement - Quantity of Parts
  • Design Requirement - Lead Time
  • Matching the Mold to the Process
  • Female vs Male vs Closed Mold
  • Matching the Mold to the Materials
  • Demolding Considerations
  • Edge Features
  • Summary of Mold Design + Design Example

CNC Machined Molds and Patterns

  • Overview of CNC Machining
  • CNC Machines
  • Cutting Tools, Machining Parameters, and Formulas
  • CAM, Toolpaths, and CNC Control Software
  • Stock
  • Work Holding
  • Work holding - Double Sided Tape
  • Work Holding - Clamps
  • Work Holding - Fasteners
  • Work Holding - Vacuum Table
  • Finishing Work
  • Mold Release
  • CNC Mold Machining Process Guide
  • Summary of CNC Machined Molds and Patterns

Making a Composite Mold from a Pattern

  • Construction Process Overview
  • Demolding Strategies
  • Inspection, Defects, and Repairs
  • Finishing Work
  • Summary

Advanced Molds and Patterns

  • Multi-Section Patterns
  • Multi-Section Molds
  • Closed Molds
  • Advanced CAM and Machining Strategies
  • High Temperature Molds
  • Summary of Advanced Molds and Patterns

Appendix

  • Terminology
  • Purchase Guide (Updated 09/04/2025)
  • Mold Release Process Guide (Updated 05/14/2024)4
  • Epoxy Gel Coat Mold Process Guide (Updated 05/31/2023)
  • Splash Mold Process Guide (Updated 05/31/2023)2
  • Fusion 360 CNC Machining CAM - Revised Sump Mold (F3D File)
  • DarkAero Aluminum Mold Support Structure Plans (Updated 06/30/2023)